The invention relates to a cableway transport installation, in particular of the bicable type, commonly referred to as back and force, back or force, or detachable cable car, or of self-propelled transfer cableway type, the installation comprising a line with one or more carrying cables on which the vehicle(s) roll(s).
This type of installation comprises terminals in which the carrying cable(s) is(are) anchored. They are in general guided on exit from the terminal on supports called “blocks”. On the line, depending on the configuration of the ground and of the installation, these carrying cables are also supported and guided on blocks arranged at the top of one or more line pillars.
The carrying cables are static, but the path of the vehicle(s) on the line causes movements of the cables inducing flexions accompanied by variations of bow and of sliding at the level of their supports. The passages of vehicles on the blocks, with more or less heavy loads per roller, create internal stresses in the cables. Consequently, all of these cable pressing points (on the line and in the terminal) are greased. This results in a better sliding of the carrying cables on the blocks and protection of their internal structure, thereby preserving their lifespan.
The pressing point areas of these carrying cables on entrance to and exit from the blocks represent areas sensitive to fatigue and damage. To limit the wear and damage of these carrying cables caused by the repeated passage of the vehicles in these areas, the standards and specifications of the manufacturers require the carrying cables to be periodically moved on their supports. The frequency of inspection of the carrying cables on terminal or line blocks can range from 6 to 12 years, depending on the type of equipment. For carrying cables subjected to large stresses, this frequency may be reduced.
It is known that repositioning of the carrying cables on the support blocks is performed by longitudinal sliding by exerting a pull on the cable from a reserve of cable, which is situated in one of the terminals. The repositioning length has to be at least equal to that of the contact area of the carrying cable on the support, increased by a safety length. The reserve of cable is generally formed by a rotary drum on which a few spirals of cable are wound. The reserve assembly has to withstand the mechanical strain of the carrying cable and requires a support structure solidly anchored to the ground of the terminal.